Search for third-generation scalar leptoquarks and heavy right-handed neutrinos in final states with two tau leptons and two jets in proton-proton collisions at root s=13 TeV

JHEP07(2017)121

Published for SISSA by Springer

Received: March 11, 2017 Revised: June 21, 2017 Accepted: July 12, 2017 Published: July 26, 2017

Search for third-generation scalar leptoquarks and

heavy right-handed neutrinos in final states with two

tau leptons and two jets in proton-proton collisions at

√

s = 13 TeV

The CMS collaboration

E-mail: cms-publication-committee-chair@cern.ch

Abstract: A search is performed for third-generation scalar leptoquarks and heavy right-handed neutrinos in events containing one electron or muon, one hadronically decaying τ lepton, and at least two jets, using a √s = 13 TeV pp collision data sample corresponding to an integrated luminosity of 12.9 fb-1 collected with the CMS detector at the LHC in 2016. The number of observed events is found to be in agreement with the standard model prediction. A limit is set at 95% confidence level on the product of the leptoquark pair production cross section and β2, where β is the branching fraction of leptoquark decay to a τ lepton and a bottom quark. Assuming β = 1, third-generation leptoquarks with masses below 850 GeV are excluded at 95% confidence level. An additional search based on the same event topology involves heavy right-handed neutrinos, NR, and right-handed

W bosons, WR, arising in a left-right symmetric extension of the standard model. In this

search, WR bosons are assumed to decay to a tau lepton and NR followed by the decay of

the NR to a tau lepton and an off-shell WR boson. Assuming the mass of the right-handed

neutrino to be half of the mass of the right-handed W boson, WR boson masses below

2.9 TeV are excluded at 95% confidence level. These results improve on the limits from previous searches for third-generation leptoquarks and heavy right-handed neutrinos with τ leptons in the final state.

Keywords: Beyond Standard Model, Hadron-Hadron scattering (experiments) ArXiv ePrint: 1703.03995

JHEP07(2017)121

Contents

1 Introduction 1

2 The CMS detector and Monte Carlo event samples 2

3 Event reconstruction and selection 3

4 Background estimation 5 5 Systematic uncertainties 6 6 Results 7 7 Summary 10 The CMS collaboration 16 1 Introduction

A number of extensions of the standard model (SM) have been proposed that predict an enhanced production rate for events containing pairs of quarks and pairs of third-generation leptons. One such theoretical proposal involves the existence of particles called leptoquarks (LQs), which carry color charge, fractional electric charge, and both lepton and baryon quantum numbers. The LQs arise in many models, including grand unified theories [1], compositeness models [2, 3], and superstring theories [4]. If LQs exist, they will decay into a lepton and a quark. At the CERN LHC, LQ pairs are predominantly produced via gluon-gluon fusion and quark-antiquark annihilation. Based on the latest experimental constraints reviewed in [5], we assume that contribution of t-channel production of LQ pairs involving Yukawa coupling of a LQ, a lepton, and a quark, is small and neglected in this analysis and the main free parameter is the mass of LQ. However, the branching fraction for the decay of a LQ into a quark and a charged lepton, β, depends on the details of the model under consideration. In this analysis we focus on the decay of a pair of third-generation LQs resulting in two τ leptons and two jets originating from b quark fragmentation.

A similar final state is expected in theories that postulate that the masses of the familiar left-handed neutrinos arise not from the Higgs field, but from a mechanism that involves the existence of right-handed neutrinos. One of the appealing features of left-right (L-R) symmetric extensions [6] of the SM is that these models predict the existence of new heavy charged (WR) and neutral (ZR) gauge bosons that could be produced at LHC

JHEP07(2017)121

energies. Heavy neutrinos (Ne, Nµ, Nτ) naturally arise as the right-handed (RH) partners

of the SM neutrinos in these L-R extensions through the see-saw mechanism [7].

In this paper, we search for these two processes by selecting final states containing two τ leptons and two jets originating from the hadronization of quarks. A search for pair production of third-generation scalar LQs is pursued by looking for events containing two τ leptons and two b quarks. We also search for the production of a WR boson from

quark-antiquark annihilation. A heavy right-handed neutrino is produced from the decay of the WRboson following the decay chain WR → τ + Nτ, where Nτ → τ + W∗_R→ τ + qq. In both

searches, we focus on signatures with one of the τ leptons decaying into an electron or a muon, referred to as a leptonic decay τ` in the following, and the other τ lepton decaying

hadronically, denoted by τh.

Previous searches for third-generation LQs have been carried out at pp, pp, e+e−, and ep colliders and the most recent results are given in [8, 9] and references therein. The most stringent lower limit on the mass of scalar third-generation LQs to date, based on the final state with two τ leptons and two b jets and assuming β = 1, is 740 GeV at 95% confidence level (CL), from the CMS experiment [10, 11]. Previous searches for heavy neutrinos have been performed at LEP [12, 13], excluding heavy neutrino masses below approximately 100 GeV. Further searches at LHC have been performed in the dielectron and dimuon channels and have excluded WRbosons with mass up to 3 TeV using data taken

at 7 TeV [14] and at 8 TeV [15]. Using 2.1 fb−1 of data of 13 TeV pp collisions collected in 2015, the CMS experiment searched for heavy neutrinos and right-handed charged bosons using events in which both τ leptons decay hadronically. That analysis excluded WR

bosons with masses below 2.35 (1.63) TeV at 95% CL, assuming the Nτ mass is 0.8 (0.2)

times the mass of WR boson [11]. In the present search, we use a

√

s = 13 TeV pp collision data sample corresponding to an integrated luminosity of 12.9 fb−1 collected with the CMS detector in 2016.

2 The CMS detector and Monte Carlo event samples

The central feature of the CMS apparatus is a superconducting solenoid of 6 m internal diameter, providing a magnetic field of 3.8 T. Within the solenoid volume are a silicon pixel and strip tracker, a lead tungstate crystal electromagnetic calorimeter (ECAL), and a brass and scintillator hadron calorimeter, each composed of a barrel and two endcap sections. Extensive forward calorimetry complements the coverage provided by the barrel and endcap detectors. Muons are detected in gas-ionisation detectors embedded in the steel flux-return yoke outside the solenoid. A detailed description of the CMS detector, together with a definition of the coordinate system used and the relevant kinematic variables, can be found in ref. [16].

The first level of the CMS triggering system, composed of custom hardware processors, uses information from the calorimeters and the muon detectors to select the most interesting events in a fixed time interval of less than 4 µs. The high-level trigger processor farm further decreases the event rate from around 100 kHz to less than 1 kHz.

JHEP07(2017)121

Background and signal processes are modeled using the following simulated samples. The pythia v8.205 generator [17] is used to model the signal and diboson (WW, WZ, and ZZ) processes. The LQ signal samples are generated with LQ masses ranging from 250 to 1500 GeV in steps of 50 GeV. The branching fraction of the LQ to a τ lepton and a bottom quark is assumed to be 100%. The signal samples are normalized to the next-to-next-to-leading order [18,19]. The WRsignal samples are generated with WRboson masses ranging

from 1000 to 4000 GeV in steps of 500 GeV and the cross sections are computed in ref. [20]. The MadGraph v5.1.5 generator [21] is used to model W+jets and Z+jets processes. Single top production and tt process are modelled with the powheg 2.0 [22–24] generator. The NNPDF 3.0 [25] Parton Distribution Functions (PDF) are used, and all simulated samples are interfaced with pythia with the CUETP8M1 tune [26] to describe parton showering and hadronization. Additional inelastic pp interactions (pileup) generated by pythia are overlaid on all simulated events, according to the luminosity profile of the analyzed data. All the generated signal and background samples are processed with the simulation of the CMS detector based on Geant4 [27]. Small differences between data and simulation in trigger, in particle identification and isolation efficiencies, and in the resolution of the pT of jets and missing transverse momentum are corrected by applying

scale factors to simulated events, as detailed below.

3 Event reconstruction and selection

The particle-flow (PF) algorithm [28, 29], which exploits information from all subdetec-tors, is used to identify individual particles, such as charged and neutral hadrons, muons, electrons, and photons. These reconstructed particles are used as input for reconstructing more complex objects such as τh candidates, jets, and variables like missing transverse

momentum.

The reconstructed interaction vertex with the largest value of P

i(piT)2, where piT is

the transverse momentum of the ith track associated with the vertex, is selected as the primary vertex of the event. This vertex is used as the reference vertex for all the objects reconstructed using the PF algorithm.

Electrons are reconstructed by matching the energy deposits in the ECAL to tracks reconstructed in the silicon pixel and strip detectors. The electrons selected in this analysis are required to have transverse momenta pT > 50 GeV and pseudorapidity |η| < 2.1 [30].

The identification and isolation of electrons are based on a multivariate technique [31] and selected electrons must satisfy tight electron identification and isolation criteria.

Muon reconstruction starts by matching tracks in the silicon tracker with tracks in the outer muon spectrometer [32]. A global muon track is fitted to the hits from both tracks. Muons are required to have pT > 50 GeV and |η| < 2.1. Quality selection criteria

are applied to the muon tracks to distinguish muons originating from particle collisions with those muons coming from cosmic rays. In addition, muons are required to pass isolation criteria to separate prompt muons from those associated with a jet, usually from the semileptonic decays of heavy quarks.

JHEP07(2017)121

The hadron-plus-strips algorithm [33,34] is used to reconstruct τhcandidates. It starts

from a jet and searches for candidates produced by the main hadronic decay modes of a τ lepton: either directly to one charged hadron, or via intermediate ρ(770) and a1(1280)

mesons to one charged hadron plus one or two neutral pions, or three charged hadrons. The reconstructed τh is required to have |η| < 2.3 and pT > 50 (pT> 60) GeV in the LQ (heavy

RH neutrino) search. Hadronic tau lepton decays are identified by a multivariate technique that uses as inputs the isolation of the τh and variables that are sensitive to its lifetime.

A selection criterion is used that has an efficiency of approximately 65% for identifying hadronically decaying tau leptons and a probability of less than 1% for misidentifying jets as hadronic tau decays. Additional criteria are applied to remove electrons and muons reconstructed as τh candidates.

The identified electron or muon and the τh are required to originate from the same

vertex and be spatially separated by ∆R ≡ √

∆φ2+ ∆η2 > 0.5. To suppress background events such as diboson and Z+jets with bosons decay giving a final state with a pair of leptons, events containing additional electron or muon candidates with pT > 15 GeV, and

which pass loose identification and isolation criteria, are rejected.

Jets are reconstructed using the anti-kT algorithm with a distance parameter of R =

0.4 [35, 36] using PF candidates. The jet energy is corrected for the average contribu-tion from particles from other proton-proton collisions in the same or neighbouring bunch crossings (pileup) [37]. Additional corrections are applied to better reflect the true total momentum of the particles in the jet [38]. Selected jets are required to be within |η| < 2.4 and have pT > 50 GeV, and to be separated from the selected electron or muon and the τh

by ∆R > 0.5. Further identification requirements are applied to distinguish genuine jets from those coming from pileup [39].

The transverse momentum imbalance, (~pmiss_T ), is calculated as the negative vectorial sum of transverse momenta of all PF candidates, and corrected by propagating the cor-rections applied to identified jets [40]. A correction is applied to account for the effect of additional pileup interactions. In addition, several filters are employed to veto events with large ~pmiss_T caused by detector effects.

Candidate events were collected using a set of triggers requiring the presence of either an electron or a muon candidate with pT > 45 GeV.

The search for LQs is based on a sample of events containing one light lepton, one τh candidate, and at least two jets. At least one of the two leading jets is identified as

originating from b quark hadronization (b-tagged) using the combined secondary vertex algorithm [41]. The chosen b tagging working point corresponds to an identification effi-ciency of approximately 70% with about 1% misidentification rate from light quarks. The lepton and τhcandidate are required to have opposite electric charge. There are two

possi-ble combinations of two tau candidates, with two jets, and the combination that minimises the difference in masses between the two resulting tau candidate-jet systems is chosen. Additionally, the invariant mass of the system formed by the visible particles of the τh

candidate and a jet is required to be greater than 250 GeV.

The search for a WR boson decaying into a heavy neutrino uses the same data sample

as used by the LQ search. The ~pmiss_T is required to be above 50 GeV and the invariant mass of the light lepton and the τh is required to be greater than 150 GeV.

JHEP07(2017)121

In the LQ analysis, the fraction of signal events passing all selection cuts ranges between 1 and 5% for masses between 300 and 1500 GeV, and in the WRanalysis the fraction varies

between 2 and 7% for masses between 1 and 4 TeV.

The presence of a signal is investigated by analysing the distribution of ST. This is

defined as the scalar sum of the pT of the electron or muon, the τhcandidate, the two jets,

and the missing transverse energy.

4 Background estimation

Several SM processes can mimic the signatures explored in this search. Production of tt pairs is the dominant background because of the presence of genuine leptons, ~pmiss_T , and both light- and heavy-flavour jets. Additionally, the production of a W or Z boson in association with jets, production of a diboson or a single top quark, and Quantum ChromoDynamics (QCD) multijet processes can also contribute to the SM background contributions.

Simulated tt events are reweighted according to the top quark pTdistribution measured

in data [42, 43]. The normalization and shape of the tt background is then verified by comparing to a data sample that consists of events containing an electron, a muon, and at least two jets and including all final selection requirements. The purity of tt events in this sample exceeds 95%. Signal contamination in this control region is found to be negligible and does not affect the comparison of data with simulation even in the tail of the ST distribution. The normalization and shape of the tt simulated sample agree well

with those observed in data. Thus, the simulation is used to predict the tt background in the signal region.

The W+jets background arises mainly from events with a genuine electron or muon originating from the leptonic decay of a W boson and an initial- or final-state radiation jet misidentified as a τh candidate. The normalization and shape of the W background are

obtained from simulation and a correction factor is applied to the normalization to take into account differences between data and simulation. The W background correction factor is estimated in a data sample that consists of W → µν events with three or more jets. One of the jets is required to pass the τh identification criteria. To reduce the contamination

from tt background, events containing jets that pass the b tagging criteria are rejected. The expected signal contamination in this sample is negligible. A binned maximum likelihood fit to the transverse mass distribution of the muon and ~pmiss_T is then performed to derive the W background normalization correction factor. The transverse mass distribution is found to have the most discriminating power for separating the W background from the other backgrounds. As an input to the fit, the normalization and shape of all other contributions are estimated from simulation. The uncertainties in the cross sections of all backgrounds are included as nuisance parameters in the fit. The contamination from QCD multijet events is small and derived from simulation. The best fit value for the W normalization correction factor is found to be 1.0 ± 0.2, with the uncertainty including both statistical and systematic components.

JHEP07(2017)121

A similar procedure is repeated for the eτhchannel in a control region containing events

with an electron and three or more jets. The W+jets normalization factor measured in W → eν events is found to be consistent with the normalization factor derived in W → µν events, albeit with a slightly larger uncertainty.

The contribution of the QCD multijet background to the signal region in both the µτh

and eτh channels is estimated from data. Events in the multijet control region are selected

by inverting the τh identification criteria: the τh candidate is required to pass looser,

but to fail tighter, identification criteria. The events are weighted by the pT-dependent

probability for a jet satisfying loose isolation criteria to pass the tight τh isolation criteria.

This probability is measured as a function of jet pT for eτh and µτh channels separately,

in independent data samples that are composed of events in which the lepton fails the isolation criteria and has the same charge as τh candidate. This probability varies from

20% for a jet pT of 50 GeV to 2% for a jet pTof 400 GeV and is similar for both final states.

In addition to the principal backgrounds, which are estimated as discussed above, other minor backgrounds, arising from single top quark, Z boson, and diboson production, are estimated from simulation. The relative contributions of all these backgrounds are given in tables 1and 2, in section 6. In these tables, the electroweak background represents the sum of the backgrounds from W+jets, Z boson, and diboson production. Additionally, for each channel the background estimation is compared with the observed data and with an estimated representative signal.

5 Systematic uncertainties

The results of the analysis are obtained from a binned fit to the ST distributions in the eτh

and µτh channels. Systematic uncertainties may affect the normalization and/or the shape

of the ST distribution of the signal and background processes.

The uncertainty in the integrated luminosity of the analysed dataset amounts to 6.2% [44]. Uncertainties in the muon and electron identification and trigger efficiency are determined using the “tag-and-probe” technique [45] and amount to 2% for identification and 5% for trigger efficiencies. The τh identification efficiency [33, 46] is measured in bins

of τh candidate pT in Z → τ τ and W → τ ν events and fitted by a linear function within

the range 20 to 200 GeV. The uncertainty in the τh identification efficiency measurement

is 6% for τ leptons from the decay of Z bosons. The extrapolation to higher transverse momenta is taken into account by adding an uncertainty that increases linearly with pT

and has a value of 20% for a pT of 200 GeV. This uncertainty has a direct effect on the

ST distribution and hence is considered as a shape uncertainty. Changes in the acceptance

due to the uncertainty in the b tagging efficiency and in the mistag rate are measured to be between 3 and 5%, depending on the process. The uncertainty in the normalization of the tt background due to the PDF and scale uncertainties amounts to 5% [47,48]. A 10% uncertainty is attributed to the Z boson background estimate, while the uncertainty in both the diboson and single top background estimates amounts to 15% [49]. The uncertainty in the yield of QCD multijet and W+jet backgrounds amounts to 30%. The uncertainty in the signal acceptance due to the choice of the PDF set in the simulated sample is evaluated

JHEP07(2017)121

in accordance to the PDF4LHC recommendations [48, 50], by comparing the results ob-tained using the CTEQ6.6L, MSTW08, and NNPDF10 PDF sets [51–53] with those from the default PDF set (CTEQ6L1). This uncertainty amounts to 5% [11].

The energy scales (ES) of the τh candidate and the associated jet affect the shape of

the ST distribution and normalization of the signal and background processes. The effects

of ES uncertainties on the analysis are estimated by varying the τh and jet energies within

their respective uncertainties and recomputing STafter the final selection. The uncertainty

in the τh ES amounts to 3% [33]. The uncertainty in the jet ES affects the pT spectrum

of the jets and consequently ~pmiss_T , and is applied to signal and all backgrounds that are estimated with MC simulation [54]. The uncertainties in the electron, muon, and ~pmiss_T ES have a negligible effect on the ST distribution. The uncertainty in the top quark pT

reweighting correction is derived by changing the event weight between zero and twice the nominal reweighting correction value [42,43]. All these three uncertainties are treated as correlated between the eτh and µτh channels.

Finally, the effects of statistical uncertainties associated with the signal and background shapes or with the numbers of events in the data control regions are included in the analysis. The statistical uncertainties are uncorrelated across the bins in each background distribution [55].

Systematic and statistical uncertainties are represented by nuisance parameters in the fit. A log-normal probability distribution function is assumed for the nuisance parameters that affect the event yields of the various background contributions. Systematic uncertain-ties affecting the ST distributions are assumed to have a Gaussian probability distribution

function. Among those uncertainties, the τh ES and high pTτhextrapolation uncertainties

are uncorrelated between the eτhand µτhchannels, because of the different τhidentification

criteria used to reduce the electron and muon mis-identification rate in each channel. The jet ES is treated as correlated across the two channels.

6 Results

A binned maximum likelihood fit to the ST distribution has been applied to the eτh and

µτh channels simultaneously. The signal production rate is constrained to the same value

in the two channels. The ST distributions for both the LQ and WR analyses are shown

in figure 1. Shape, normalization and uncertainty are shown for the values of nuisances parameters obtained from the fit. No excess is seen above the SM expectation within the statistical and systematic uncertainties in both searches. The event yields observed in the leptoquark analysis and in the heavy right-handed W boson analysis are shown in tables 1

and 2, respectively, and compared to background expectations and to the estimated event yields for representative signals.

Upper limits on the product of the cross section and branching fractions are set at 95% CL using a modified frequentist criterion CLs [56, 57], based on the binned distribution

of the ST variable. Figure 2 (left) shows the observed and expected 95% CL upper limit

on the product of cross section and branching fraction in the LQ analysis. The observed (expected) 95% CL mass limit for third-generation scalar LQ is determined to be 850

JHEP07(2017)121

Events / GeV 5 − 10 4 − 10 3 − 10 2 − 10 1 − 10 1 10 2 10 ObservedLQ 900 GeV +jets t t SingleTop Electroweak QCD multijet Uncertainty (13 TeV) -1 12.9 fb CMS h τ µ [GeV] T S 3 10 Obs./Exp. 0.5 1 1.5 Events / GeV 5 − 10 4 − 10 3 − 10 2 − 10 1 − 10 1 10 2 10 ObservedLQ 900 GeV +jets t t SingleTop Electroweak QCD multijet Uncertainty (13 TeV) -1 12.9 fb CMS h τ e [GeV] T S 3 10 Obs./Exp. 0.5 1 1.5 Events / GeV 5 − 10 4 − 10 3 − 10 2 − 10 1 − 10 1 10 2 10 ObservedRH W 3TeV +jets t t SingleTop Electroweak QCD multijet Uncertainty (13 TeV) -1 12.9 fb CMS h τ µ [GeV] T S 3 10 Obs./Exp. 0.5 1 1.5 Events / GeV 5 − 10 4 − 10 3 − 10 2 − 10 1 − 10 1 10 2 10 ObservedRH W 3TeV +jets t t SingleTop Electroweak QCD multijet Uncertainty (13 TeV) -1 12.9 fb CMS h τ e [GeV] T S 3 10 Obs./Exp. 0.5 1 1.5

Figure 1. Measured STdistribution in the µτh(left) and eτh (right) channels of the LQ (upper) and heavy RH neutrino (lower) analyses, compared to the expected SM background contribution. A hypothetical LQ signal of mass MLQ= 900 GeV and a hypothetical heavy WR signal of mass MWR= 3 TeV are overlaid to illustrate the sensitivity. The electroweak background represents the

sum of W boson, Z boson, and diboson production. The last bin of each plot contains overflow events. A binned maximum likelihood fit is performed on the ST distribution. The uncertainty bands represent the sum in quadrature of statistical and systematic uncertainties, obtained from the fit. The lower panels in all plots compare the observed and expected events in each bin.

JHEP07(2017)121

Process eτh µτh tt +jets 136.8 ± 13.2 145.6 ± 14.6 SingleTop 15.7 ± 3.1 27.6 ± 4.5 Electroweak 69.6 ± 10.5 53.3 ± 9.0 QCD multijet 25.0 ± 6.8 28.9 ± 7.4 Total expected background 247.1 ± 16.8 255.4 ± 16.1

LQ 900 GeV 6.0 ± 0.3 5.7 ± 0.2

Observed data 249 250

Table 1. Number of events observed in the eτhand µτhchannels of the LQ analysis compared to the background expectations and to the event yield expected for a representative LQ signal of mass 900 GeV. The quoted uncertainties represent the sum of statistical and systematic uncertainties and are obtained by the binned maximum likelihood fit of the distribution in ST, as described in the text. Process eτh µτh tt +jets 456.2 ± 25.8 557.6 ± 30.7 SingleTop 41.6 ± 7.1 47.6 ± 8.1 Electroweak 60.2 ± 26.8 83.6 ± 33.2 QCD multijet 48.6 ± 13.1 65.7 ± 16.8 Total expected background 606.6 ± 33.5 754.5 ± 38.7 RHW 3000 GeV 4.8 ± 0.3 3.5 ± 0.3

Observed data 606 751

Table 2. Number of events observed in the eτh and µτh channels of the heavy right-handed W analysis compared to the background expectations and to the event yield expected for a represen-tative right-handed W boson signal of mass 3 TeV. The quoted uncertainties represent the sum of statistical and systematic uncertainties and are obtained by the binned maximum likelihood fit of the distribution in ST, as described in the text.

(900) GeV, respectively, assuming β = 1, namely a 100% branching fraction for the LQ to decay into a τ lepton and a bottom quark. Figure 2 (right) shows the 95% CL observed and expected exclusion limits on the LQ mass, as a function of β.

Figure3(left) shows the observed and expected upper limits at 95% CL on the product of cross section and branching fraction for the WR → τ Nτ analysis. Assuming the mass

of the neutrino to be half the mass of the WR boson, the observed (expected) limit at

95% CL on the mass of heavy right-handed WR bosons is determined to be 2.9 (3.0) TeV,

respectively. Figure 3 (right) shows the observed and expected 95% CL upper limits on the production cross section as functions of MWR and MNτ. The blue curve in the left plot represent the theoretical production cross section of WR boson times branching fraction of

the WR boson to a τ lepton and RH neutrino, assuming mass of RH neutrino to be half

JHEP07(2017)121

=1) β Theory ( Observed Expected 68% expected 95% expected [GeV] LQ M 200 400 600 800 1000 1200 1400 [pb] 2 β⋅ σ 4 − 10 3 − 10 2 − 10 1 − 10 1 10 2 10 3 10 (13 TeV) -1 12.9 fb CMS [GeV] LQ M 200 300 400 500 600 700 800 900 1000 β 0 0.2 0.4 0.6 0.8 1 (13 TeV) -1 12.9 fb CMS Observed exclusion Median expected limit 68% expected limit

Figure 2. Observed and expected limits at 95% CL on the product of cross section and branching fraction squared, obtained from the combination of the eτh and µτh channels, in the LQ analy-sis (left) and 95% CL observed and expected exclusion limits on the LQ mass, as a function of β(right). In the left plot, the green and yellow bands represent the one and two standard deviation uncertainties in the expected limits. The dashed dark blue curve represents the theoretical LQ pair production cross section, assuming β = 100% [18,19]. In the right plot, the grey band represents the one standard deviation uncertainty in the expected limit.

7 Summary

Searches have been performed for third-generation scalar leptoquarks and for heavy right-handed neutrinos in events containing one electron or muon, one hadronically decaying τ lepton, and two or more jets, using pp collision data at√s = 13 TeV, recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 12.9 fb−1. The data are found to be in good agreement with the standard model prediction in both analyses. A limit at 95% confidence level is set on the product of the leptoquark pair production cross section and β2, where β denotes the branching fraction for the decay of the leptoquark into a τ lepton and a bottom quark. Assuming β = 1, third-generation leptoquarks with masses below 850 GeV are excluded at 95% confidence level. In the heavy RH neutrino analysis, considering the decay WR → τ NR and assuming the mass of the heavy neutrino

to be half the mass of the WR boson, we exclude WR boson masses below 2.9 TeV at 95%

confidence level. These are the best mass limits to date for third-generation leptoquarks and heavy right-handed neutrinos with τ leptons in the final state.

Acknowledgments

We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC and thank the technical and administrative staffs at CERN and

JHEP07(2017)121

/2) W = M N Theory (M Observed Expected 68% expected 95% expected [GeV] R W M 1000 1500 2000 2500 3000 3500 4000 jj)[pb] τ τ → R (W Β ×) R W → (pp σ 3 − 10 2 − 10 1 − 10 1 10 (13 TeV) -1 12.9 fb CMS 10 [GeV] R W M 2000 3000 4000 [GeV] τ N M 1000 2000 3000 Observed Expected (13 TeV) -1 12.9 fb CMS

Cross section upper limit at 95% CL [fb]

Figure 3. Observed and expected limits at 95% CL on the product of cross section and branching fraction, obtained from the combination of the eτh and µτh channels in the heavy right-handed neutrino analysis (left) and the observed and expected limits at 95% CL on the production cross section as a function of MWR and MNR (right). The green and yellow bands represent the one

and two standard deviation uncertainties in the expected limits. The dashed dark blue curve represents the theoretical prediction for the product of the WRboson production cross section and the branching fraction for decay to a τ lepton and RH neutrino, assuming the mass of the RH neutrino to be half the mass of the WR boson [20].

at other CMS institutes for their contributions to the success of the CMS effort. In ad-dition, we gratefully acknowledge the computing centres and personnel of the Worldwide LHC Computing Grid for delivering so effectively the computing infrastructure essential to our analyses. Finally, we acknowledge the enduring support for the construction and operation of the LHC and the CMS detector provided by the following funding agencies: BMWFW and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COL-CIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus); SENESCYT (Ecuador); MoER, ERC IUT, and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NIH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS, RFBR and RAEP (Russia); MESTD (Serbia); SEIDI, CPAN, PCTI and FEDER (Spain); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter, IPST, STAR, and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE and NSF (U.S.A.).

Individuals have received support from the Marie-Curie programme and the Euro-pean Research Council and EPLANET (EuroEuro-pean Union); the Leventis Foundation; the

JHEP07(2017)121

A.P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation `a la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Council of Science and Industrial Research, India; the HOM-ING PLUS programme of the Foundation for Polish Science, cofinanced from Euro-pean Union, Regional Development Fund, the Mobility Plus programme of the Min-istry of Science and Higher Education, the National Science Center (Poland), contracts Harmonia 2014/14/M/ST2/00428, Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and 2015/19/B/ST2/02861, Sonata-bis 2012/07/E/ST2/01406; the National Priorities Re-search Program by Qatar National ReRe-search Fund; the Programa Clar´ın-COFUND del Principado de Asturias; the Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); and the Welch Foundation, contract C-1845.

Open Access. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.

References

[1] H. Georgi and S.L. Glashow, Unity of All Elementary Particle Forces,Phys. Rev. Lett. 32 (1974) 438[INSPIRE].

[2] B. Schrempp and F. Schrempp, Light leptoquarks,Phys. Lett. B 153 (1985) 101[INSPIRE].

[3] W. Buchm¨uller, R. R¨uckl and D. Wyler, Leptoquarks in lepton-quark collisions,Phys. Lett. B 191 (1987) 442[Erratum ibid. B 448 (1999) 320] [INSPIRE].

[4] J.L. Hewett and T.G. Rizzo, Low-Energy Phenomenology of Superstring Inspired E6 Models, Phys. Rept. 183 (1989) 193[INSPIRE].

[5] I. Dorˇsner, S. Fajfer, A. Greljo, J.F. Kamenik and N. Koˇsnik, Physics of leptoquarks in precision experiments and at particle colliders,Phys. Rept. 641 (2016) 1[arXiv:1603.04993] [INSPIRE].

[6] R.N. Mohapatra and J.C. Pati, A Natural Left-Right Symmetry,Phys. Rev. D 11 (1975) 2558[INSPIRE].

[7] W.-Y. Keung and G. Senjanovi´c, Majorana Neutrinos and the Production of the Right-handed Charged Gauge Boson,Phys. Rev. Lett. 50 (1983) 1427 [INSPIRE].

[8] ATLAS collaboration, Search for third generation scalar leptoquarks in pp collisions at_√ s = 7 TeV with the ATLAS detector, JHEP 06 (2013) 033[arXiv:1303.0526] [INSPIRE].

[9] CMS collaboration, Search for pair production of third-generation scalar leptoquarks and top squarks in proton-proton collisions at√s = 8 TeV,Phys. Lett. B 739 (2014) 229

JHEP07(2017)121

[10] CMS collaboration, Search for pair production of third-generation leptoquarks and top

squarks in pp collisions at √s = 7 TeV,Phys. Rev. Lett. 110 (2013) 081801 [arXiv:1210.5629] [INSPIRE].

[11] CMS collaboration, Search for heavy neutrinos or third-generation leptoquarks in final states with two hadronically decaying τ leptons and two jets in proton-proton collisions at

√

s = 13 TeV,JHEP 03 (2017) 077[arXiv:1612.01190] [INSPIRE].

[12] DELPHI collaboration, P. Abreu et al., Search for neutral heavy leptons produced in Z decays,Z. Phys. C 74 (1997) 57[Erratum ibid. C 75 (1997) 580] [INSPIRE].

[13] L3 collaboration, O. Adriani et al., Search for isosinglet neutral heavy leptons in Z0 decays, Phys. Lett. B 295 (1992) 371[INSPIRE].

[14] ATLAS collaboration, Search for heavy neutrinos and right-handed W bosons in events with two leptons and jets in pp collisions at√s = 7 TeV with the ATLAS detector,Eur. Phys. J. C 72 (2012) 2056[arXiv:1203.5420] [INSPIRE].

[15] CMS collaboration, Search for heavy neutrinos and W bosons with right-handed couplings in proton-proton collisions at√s = 8 TeV,Eur. Phys. J. C 74 (2014) 3149[arXiv:1407.3683] [INSPIRE].

[16] CMS collaboration, The CMS Experiment at the CERN LHC,2008 JINST 3 S08004 [INSPIRE].

[17] T. Sj¨ostrand et al., An Introduction to PYTHIA 8.2, Comput. Phys. Commun. 191 (2015) 159[arXiv:1410.3012] [INSPIRE].

[18] M. Kr¨amer, T. Plehn, M. Spira and P.M. Zerwas, Pair production of scalar leptoquarks at the CERN LHC,Phys. Rev. D 71 (2005) 057503[hep-ph/0411038] [INSPIRE].

[19] M. Kr¨amer, T. Plehn, M. Spira and P.M. Zerwas, Pair production of scalar leptoquarks at the Tevatron,Phys. Rev. Lett. 79 (1997) 341[hep-ph/9704322] [INSPIRE].

[20] F. del Aguila, J.A. Aguilar-Saavedra and R. Pittau, Heavy neutrino signals at large hadron colliders,JHEP 10 (2007) 047[hep-ph/0703261] [INSPIRE].

[21] F. Maltoni and T. Stelzer, MadEvent: Automatic event generation with MadGraph,JHEP 02 (2003) 027[hep-ph/0208156] [INSPIRE].

[22] P. Nason, A New method for combining NLO QCD with shower Monte Carlo algorithms, JHEP 11 (2004) 040[hep-ph/0409146] [INSPIRE].

[23] S. Frixione, P. Nason and C. Oleari, Matching NLO QCD computations with Parton Shower simulations: the POWHEG method,JHEP 11 (2007) 070[arXiv:0709.2092] [INSPIRE].

[24] S. Alioli, P. Nason, C. Oleari and E. Re, A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX,JHEP 06 (2010) 043 [arXiv:1002.2581] [INSPIRE].

[25] NNPDF collaboration, R.D. Ball et al., Parton distributions for the LHC Run II,JHEP 04 (2015) 040[arXiv:1410.8849] [INSPIRE].

[26] CMS collaboration, Event generator tunes obtained from underlying event and multiparton scattering measurements,Eur. Phys. J. C 76 (2016) 155[arXiv:1512.00815] [INSPIRE].

[27] GEANT4 collaboration, S. Agostinelli et al., GEANT4 — a simulation toolkit, Nucl. Instrum. Meth. A 506 (2003) 250[INSPIRE].

JHEP07(2017)121

[28] CMS collaboration, Particle-Flow Event Reconstruction in CMS and Performance for Jets,

Taus and MET,CMS-PAS-PFT-09-001(2009) [INSPIRE].

[29] CMS collaboration, Commissioning of the Particle-flow Event Reconstruction with the first LHC collisions recorded in the CMS detector,CMS-PAS-PFT-10-001(2010) [INSPIRE].

[30] CMS collaboration, Performance of Electron Reconstruction and Selection with the CMS Detector in Proton-Proton Collisions at√s = 8 TeV,2015 JINST 10 P06005

[arXiv:1502.02701] [INSPIRE].

[31] H. Voss, A. H¨ocker, J. Stelzer and F. Tegenfeldt, TMVA: Toolkit for Multivariate Data Analysis with ROOT,PoS(ACAT)040[physics/0703039] [INSPIRE].

[32] CMS collaboration, Performance of CMS muon reconstruction in pp collision events at_√ s = 7 TeV,2012 JINST 7 P10002[arXiv:1206.4071] [INSPIRE].

[33] CMS collaboration, Reconstruction and identification of τ lepton decays to hadrons and ντ at CMS,2016 JINST 11 P01019 [arXiv:1510.07488] [INSPIRE].

[34] CMS collaboration, Performance of reconstruction and identification of tau leptons in their decays to hadrons and tau neutrino in LHC Run-2,CMS-PAS-TAU-16-002(2016) [INSPIRE].

[35] G.P. Salam, Towards Jetography,Eur. Phys. J. C 67 (2010) 637[arXiv:0906.1833] [INSPIRE].

[36] M. Cacciari, G.P. Salam and G. Soyez, The Anti-kt jet clustering algorithm,JHEP 04 (2008) 063[arXiv:0802.1189] [INSPIRE].

[37] CMS collaboration, Pileup Removal Algorithms, CMS-PAS-JME-14-001(2014) [INSPIRE].

[38] CMS collaboration, Jet energy scale and resolution in the CMS experiment in pp collisions at 8 TeV,2017 JINST 12 P02014 [arXiv:1607.03663] [INSPIRE].

[39] CMS collaboration, Pileup Jet Identification,CMS-PAS-JME-13-005(2013) [INSPIRE].

[40] CMS collaboration, Performance of missing energy reconstruction in 13 TeV pp collision data using the CMS detector,CMS-PAS-JME-16-004(2016) [INSPIRE].

[41] CMS collaboration, Identification of b quark jets at the CMS Experiment in the LHC Run 2, CMS-PAS-BTV-15-001(2016) [INSPIRE].

[42] CMS collaboration, Measurement of the differential cross section for top quark pair production in pp collisions at√s = 8 TeV,Eur. Phys. J. C 75 (2015) 542

[arXiv:1505.04480] [INSPIRE].

[43] CMS collaboration, Measurement of differential top-quark pair production cross sections in pp colisions at√s = 7 TeV,Eur. Phys. J. C 73 (2013) 2339[arXiv:1211.2220] [INSPIRE].

[44] CMS collaboration, CMS luminosity measurement for the 2015 data-taking period, CMS-PAS-LUM-15-001(2016) [INSPIRE].

[45] CMS collaboration, Measurement of the Inclusive W and Z Production Cross Sections in pp Collisions at√s = 7 TeV,JHEP 10 (2011) 132[arXiv:1107.4789] [INSPIRE].

[46] CMS collaboration, Performance of τ -lepton reconstruction and identification in CMS,2012 JINST 7 P01001[arXiv:1109.6034] [INSPIRE].

[47] M. Czakon and A. Mitov, Top++: A Program for the Calculation of the Top-Pair Cross-Section at Hadron Colliders,Comput. Phys. Commun. 185 (2014) 2930 [arXiv:1112.5675] [INSPIRE].

JHEP07(2017)121

[48] M. Botje et al., The PDF4LHC Working Group Interim Recommendations,

arXiv:1101.0538[INSPIRE].

[49] CMS collaboration, Measurement of W+_W− _{and ZZ production cross sections in pp} collisions at √s = 8 TeV,Phys. Lett. B 721 (2013) 190[arXiv:1301.4698] [INSPIRE].

[50] S. Alekhin et al., The PDF4LHC Working Group Interim Report,arXiv:1101.0536 [INSPIRE].

[51] P.M. Nadolsky et al., Implications of CTEQ global analysis for collider observables,Phys. Rev. D 78 (2008) 013004[arXiv:0802.0007] [INSPIRE].

[52] A.D. Martin, W.J. Stirling, R.S. Thorne and G. Watt, Update of parton distributions at NNLO,Phys. Lett. B 652 (2007) 292[arXiv:0706.0459] [INSPIRE].

[53] M. Ubiali, NNPDF1.0 parton set for the LHC, in proceedings of the 14th High-Energy Physics International Conference on Quantum Chromodynamics (QCD 08), Montpellier, France, 7–12 July 2008, p. 62 [Nucl. Phys. Proc. Suppl. 186 (2009) 62] [arXiv:0809.3716] [INSPIRE].

[54] CMS collaboration, Determination of Jet Energy Calibration and Transverse Momentum Resolution in CMS,2011 JINST 6 P11002[arXiv:1107.4277] [INSPIRE].

[55] R.J. Barlow and C. Beeston, Fitting using finite Monte Carlo samples,Comput. Phys. Commun. 77 (1993) 219[INSPIRE].

[56] T. Junk, Confidence level computation for combining searches with small statistics,Nucl. Instrum. Meth. A 434 (1999) 435[hep-ex/9902006] [INSPIRE].

[57] A.L. Read, Presentation of search results: The CLstechnique, J. Phys. G 28 (2002) 2693 [INSPIRE].

JHEP07(2017)121

The CMS collaboration

Yerevan Physics Institute, Yerevan, Armenia A.M. Sirunyan, A. Tumasyan

Institut f¨ur Hochenergiephysik, Wien, Austria

W. Adam, E. Asilar, T. Bergauer, J. Brandstetter, E. Brondolin, M. Dragicevic, J. Er¨o, M. Flechl, M. Friedl, R. Fr¨uhwirth1, V.M. Ghete, C. Hartl, N. H¨ormann, J. Hrubec, M. Jeitler1, A. K¨onig, I. Kr¨atschmer, D. Liko, T. Matsushita, I. Mikulec, D. Rabady, N. Rad, B. Rahbaran, H. Rohringer, J. Schieck1, J. Strauss, W. Waltenberger, C.-E. Wulz1 Institute for Nuclear Problems, Minsk, Belarus

O. Dvornikov, V. Makarenko, V. Mossolov, J. Suarez Gonzalez, V. Zykunov National Centre for Particle and High Energy Physics, Minsk, Belarus N. Shumeiko

Universiteit Antwerpen, Antwerpen, Belgium

S. Alderweireldt, E.A. De Wolf, X. Janssen, J. Lauwers, M. Van De Klundert, H. Van Haevermaet, P. Van Mechelen, N. Van Remortel, A. Van Spilbeeck

Vrije Universiteit Brussel, Brussel, Belgium

S. Abu Zeid, F. Blekman, J. D’Hondt, N. Daci, I. De Bruyn, K. Deroover, S. Lowette, S. Moortgat, L. Moreels, A. Olbrechts, Q. Python, K. Skovpen, S. Tavernier, W. Van Doninck, P. Van Mulders, I. Van Parijs

Universit´e Libre de Bruxelles, Bruxelles, Belgium

H. Brun, B. Clerbaux, G. De Lentdecker, H. Delannoy, G. Fasanella, L. Favart, R. Goldouzian, A. Grebenyuk, G. Karapostoli, T. Lenzi, A. L´eonard, J. Luetic, T. Maer-schalk, A. Marinov, A. Randle-conde, T. Seva, C. Vander Velde, P. Vanlaer, D. Vannerom, R. Yonamine, F. Zenoni, F. Zhang2

Ghent University, Ghent, Belgium

T. Cornelis, D. Dobur, A. Fagot, M. Gul, I. Khvastunov, D. Poyraz, S. Salva, R. Sch¨ofbeck, M. Tytgat, W. Van Driessche, E. Yazgan, N. Zaganidis

Universit´e Catholique de Louvain, Louvain-la-Neuve, Belgium

H. Bakhshiansohi, C. Beluffi3, O. Bondu, S. Brochet, G. Bruno, A. Caudron, S. De Visscher, C. Delaere, M. Delcourt, B. Francois, A. Giammanco, A. Jafari, M. Komm, G. Krintiras, V. Lemaitre, A. Magitteri, A. Mertens, M. Musich, K. Piotrzkowski, L. Quertenmont, M. Selvaggi, M. Vidal Marono, S. Wertz

Universit´e de Mons, Mons, Belgium N. Beliy

Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil

W.L. Ald´a J´unior, F.L. Alves, G.A. Alves, L. Brito, C. Hensel, A. Moraes, M.E. Pol, P. Rebello Teles

JHEP07(2017)121

Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil

E. Belchior Batista Das Chagas, W. Carvalho, J. Chinellato4, A. Cust´odio, E.M. Da Costa, G.G. Da Silveira5, D. De Jesus Damiao, C. De Oliveira Martins, S. Fonseca De Souza, L.M. Huertas Guativa, H. Malbouisson, D. Matos Figueiredo, C. Mora Herrera, L. Mundim, H. Nogima, W.L. Prado Da Silva, A. Santoro, A. Sznajder, E.J. Tonelli Manganote4, F. Torres Da Silva De Araujo, A. Vilela Pereira

Universidade Estadual Paulistaa, Universidade Federal do ABCb, S˜ao Paulo, Brazil

S. Ahujaa, C.A. Bernardesa, S. Dograa, T.R. Fernandez Perez Tomeia, E.M. Gregoresb, P.G. Mercadanteb, C.S. Moona, S.F. Novaesa, Sandra S. Padulaa, D. Romero Abadb, J.C. Ruiz Vargasa

Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria

A. Aleksandrov, R. Hadjiiska, P. Iaydjiev, M. Rodozov, S. Stoykova, G. Sultanov, M. Vu-tova

University of Sofia, Sofia, Bulgaria

A. Dimitrov, I. Glushkov, L. Litov, B. Pavlov, P. Petkov Beihang University, Beijing, China

W. Fang6

Institute of High Energy Physics, Beijing, China

M. Ahmad, J.G. Bian, G.M. Chen, H.S. Chen, M. Chen, Y. Chen7, T. Cheng, C.H. Jiang, D. Leggat, Z. Liu, F. Romeo, M. Ruan, S.M. Shaheen, A. Spiezia, J. Tao, C. Wang, Z. Wang, H. Zhang, J. Zhao

State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China

Y. Ban, G. Chen, Q. Li, S. Liu, Y. Mao, S.J. Qian, D. Wang, Z. Xu Universidad de Los Andes, Bogota, Colombia

C. Avila, A. Cabrera, L.F. Chaparro Sierra, C. Florez, J.P. Gomez, C.F. Gonz´alez Hern´andez, J.D. Ruiz Alvarez8, J.C. Sanabria

University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Split, Croatia

N. Godinovic, D. Lelas, I. Puljak, P.M. Ribeiro Cipriano, T. Sculac University of Split, Faculty of Science, Split, Croatia Z. Antunovic, M. Kovac

Institute Rudjer Boskovic, Zagreb, Croatia V. Brigljevic, D. Ferencek, K. Kadija, B. Mesic, T. Susa University of Cyprus, Nicosia, Cyprus

M.W. Ather, A. Attikis, G. Mavromanolakis, J. Mousa, C. Nicolaou, F. Ptochos, P.A. Razis, H. Rykaczewski

JHEP07(2017)121

Charles University, Prague, Czech Republic M. Finger9, M. Finger Jr.9

Universidad San Francisco de Quito, Quito, Ecuador E. Carrera Jarrin

Academy of Scientific Research and Technology of the Arab Republic of Egypt, Egyptian Network of High Energy Physics, Cairo, Egypt

A. Ellithi Kamel10, M.A. Mahmoud11,12, A. Radi12,13

National Institute of Chemical Physics and Biophysics, Tallinn, Estonia M. Kadastik, L. Perrini, M. Raidal, A. Tiko, C. Veelken

Department of Physics, University of Helsinki, Helsinki, Finland P. Eerola, J. Pekkanen, M. Voutilainen

Helsinki Institute of Physics, Helsinki, Finland

J. H¨ark¨onen, T. J¨arvinen, V. Karim¨aki, R. Kinnunen, T. Lamp´en, K. Lassila-Perini, S. Lehti, T. Lind´en, P. Luukka, J. Tuominiemi, E. Tuovinen, L. Wendland

Lappeenranta University of Technology, Lappeenranta, Finland J. Talvitie, T. Tuuva

IRFU, CEA, Universit´e Paris-Saclay, Gif-sur-Yvette, France

M. Besancon, F. Couderc, M. Dejardin, D. Denegri, B. Fabbro, J.L. Faure, C. Favaro, F. Ferri, S. Ganjour, S. Ghosh, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry, I. Kucher, E. Locci, M. Machet, J. Malcles, J. Rander, A. Rosowsky, M. Titov

Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France

A. Abdulsalam, I. Antropov, S. Baffioni, F. Beaudette, P. Busson, L. Cadamuro, E. Chapon, C. Charlot, O. Davignon, R. Granier de Cassagnac, M. Jo, S. Lisniak, P. Min´e, M. Nguyen, C. Ochando, G. Ortona, P. Paganini, P. Pigard, S. Regnard, R. Salerno, Y. Sirois, A.G. Stahl Leiton, T. Strebler, Y. Yilmaz, A. Zabi, A. Zghiche

Institut Pluridisciplinaire Hubert Curien (IPHC), Universit´e de Strasbourg, CNRS-IN2P3

J.-L. Agram14, J. Andrea, D. Bloch, J.-M. Brom, M. Buttignol, E.C. Chabert, N. Chanon, C. Collard, E. Conte14_{, X. Coubez, J.-C. Fontaine}14_{, D. Gel´e, U. Goerlach, A.-C. Le Bihan,}

P. Van Hove

Centre de Calcul de l’Institut National de Physique Nucleaire et de Physique des Particules, CNRS/IN2P3, Villeurbanne, France

S. Gadrat

Universit´e de Lyon, Universit´e Claude Bernard Lyon 1, CNRS-IN2P3, Institut de Physique Nucl´eaire de Lyon, Villeurbanne, France

S. Beauceron, C. Bernet, G. Boudoul, C.A. Carrillo Montoya, R. Chierici, D. Contardo, B. Courbon, P. Depasse, H. El Mamouni, J. Fay, S. Gascon, M. Gouzevitch, G. Grenier,

JHEP07(2017)121

B. Ille, F. Lagarde, I.B. Laktineh, M. Lethuillier, L. Mirabito, A.L. Pequegnot, S. Perries, A. Popov15, V. Sordini, M. Vander Donckt, P. Verdier, S. Viret

Georgian Technical University, Tbilisi, Georgia A. Khvedelidze9

Tbilisi State University, Tbilisi, Georgia Z. Tsamalaidze9

RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany

C. Autermann, S. Beranek, L. Feld, M.K. Kiesel, K. Klein, M. Lipinski, M. Preuten, C. Schomakers, J. Schulz, T. Verlage

RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany A. Albert, M. Brodski, E. Dietz-Laursonn, D. Duchardt, M. Endres, M. Erdmann, S. Erd-weg, T. Esch, R. Fischer, A. G¨uth, M. Hamer, T. Hebbeker, C. Heidemann, K. Hoepfner, S. Knutzen, M. Merschmeyer, A. Meyer, P. Millet, S. Mukherjee, M. Olschewski, K. Padeken, T. Pook, M. Radziej, H. Reithler, M. Rieger, F. Scheuch, L. Sonnenschein, D. Teyssier, S. Th¨uer

RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany V. Cherepanov, G. Fl¨ugge, B. Kargoll, T. Kress, A. K¨unsken, J. Lingemann, T. M¨uller, A. Nehrkorn, A. Nowack, C. Pistone, O. Pooth, A. Stahl16

Deutsches Elektronen-Synchrotron, Hamburg, Germany

M. Aldaya Martin, T. Arndt, C. Asawatangtrakuldee, K. Beernaert, O. Behnke, U. Behrens, A.A. Bin Anuar, K. Borras17, A. Campbell, P. Connor, C. Contreras-Campana, F. Costanza, C. Diez Pardos, G. Dolinska, G. Eckerlin, D. Eckstein, T. Eichhorn, E. Eren, E. Gallo18, J. Garay Garcia, A. Geiser, A. Gizhko, J.M. Grados Luyando, A. Grohsjean, P. Gunnellini, A. Harb, J. Hauk, M. Hempel19, H. Jung, A. Kalogeropoulos, O. Karacheban19, M. Kasemann, J. Keaveney, C. Kleinwort, I. Korol, D. Kr¨ucker, W. Lange, A. Lelek, T. Lenz, J. Leonard, K. Lipka, A. Lobanov, W. Lohmann19, R. Mankel, I.-A. Melzer-Pellmann, A.B. Meyer, G. Mittag, J. Mnich, A. Mussgiller, D. Pitzl, R. Placakyte, A. Raspereza, B. Roland, M. ¨O. Sahin, P. Saxena, T. Schoerner-Sadenius, S. Spannagel, N. Stefaniuk, G.P. Van Onsem, R. Walsh, C. Wissing

University of Hamburg, Hamburg, Germany

V. Blobel, M. Centis Vignali, A.R. Draeger, T. Dreyer, E. Garutti, D. Gonzalez, J. Haller, M. Hoffmann, A. Junkes, R. Klanner, R. Kogler, N. Kovalchuk, T. Lapsien, I. Marchesini, D. Marconi, M. Meyer, M. Niedziela, D. Nowatschin, F. Pantaleo16, T. Peiffer, A. Perieanu, C. Scharf, P. Schleper, A. Schmidt, S. Schumann, J. Schwandt, H. Stadie, G. Steinbr¨uck, F.M. Stober, M. St¨over, H. Tholen, D. Troendle, E. Usai, L. Vanelderen, A. Vanhoefer, B. Vormwald

Institut f¨ur Experimentelle Kernphysik, Karlsruhe, Germany

M. Akbiyik, C. Barth, S. Baur, C. Baus, J. Berger, E. Butz, R. Caspart, T. Chwalek, F. Colombo, W. De Boer, A. Dierlamm, S. Fink, B. Freund, R. Friese, M. Giffels, A. Gilbert,

JHEP07(2017)121

P. Goldenzweig, D. Haitz, F. Hartmann16, S.M. Heindl, U. Husemann, F. Kassel16, I. Katkov15, S. Kudella, H. Mildner, M.U. Mozer, Th. M¨uller, M. Plagge, G. Quast, K. Rabbertz, S. R¨ocker, F. Roscher, M. Schr¨oder, I. Shvetsov, G. Sieber, H.J. Simonis, R. Ulrich, S. Wayand, M. Weber, T. Weiler, S. Williamson, C. W¨ohrmann, R. Wolf Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia Paraskevi, Greece

G. Anagnostou, G. Daskalakis, T. Geralis, V.A. Giakoumopoulou, A. Kyriakis, D. Loukas, I. Topsis-Giotis

National and Kapodistrian University of Athens, Athens, Greece S. Kesisoglou, A. Panagiotou, N. Saoulidou, E. Tziaferi

University of Io´annina, Io´annina, Greece

I. Evangelou, G. Flouris, C. Foudas, P. Kokkas, N. Loukas, N. Manthos, I. Papadopoulos, E. Paradas

MTA-ELTE Lend¨ulet CMS Particle and Nuclear Physics Group, E¨otv¨os Lor´and University, Budapest, Hungary

N. Filipovic, G. Pasztor

Wigner Research Centre for Physics, Budapest, Hungary

G. Bencze, C. Hajdu, D. Horvath20, F. Sikler, V. Veszpremi, G. Vesztergombi21, A.J. Zsig-mond

Institute of Nuclear Research ATOMKI, Debrecen, Hungary N. Beni, S. Czellar, J. Karancsi22_{, A. Makovec, J. Molnar, Z. Szillasi}

Institute of Physics, University of Debrecen M. Bart´ok21_{, P. Raics, Z.L. Trocsanyi, B. Ujvari}

Indian Institute of Science (IISc) J.R. Komaragiri

National Institute of Science Education and Research, Bhubaneswar, India S. Bahinipati23_{, S. Bhowmik}24_{, S. Choudhury}25_{, P. Mal, K. Mandal, A. Nayak}26_,

D.K. Sahoo23, N. Sahoo, S.K. Swain Panjab University, Chandigarh, India

S. Bansal, S.B. Beri, V. Bhatnagar, R. Chawla, U.Bhawandeep, A.K. Kalsi, A. Kaur, M. Kaur, R. Kumar, P. Kumari, A. Mehta, M. Mittal, J.B. Singh, G. Walia

University of Delhi, Delhi, India

Ashok Kumar, A. Bhardwaj, B.C. Choudhary, R.B. Garg, S. Keshri, S. Malhotra, M. Naimuddin, K. Ranjan, R. Sharma, V. Sharma

Saha Institute of Nuclear Physics, Kolkata, India

R. Bhattacharya, S. Bhattacharya, K. Chatterjee, S. Dey, S. Dutt, S. Dutta, S. Ghosh, N. Majumdar, A. Modak, K. Mondal, S. Mukhopadhyay, S. Nandan, A. Purohit, A. Roy, D. Roy, S. Roy Chowdhury, S. Sarkar, M. Sharan, S. Thakur

JHEP07(2017)121

Indian Institute of Technology Madras, Madras, India P.K. Behera

Bhabha Atomic Research Centre, Mumbai, India

R. Chudasama, D. Dutta, V. Jha, V. Kumar, A.K. Mohanty16, P.K. Netrakanti, L.M. Pant, P. Shukla, A. Topkar

Tata Institute of Fundamental Research-A, Mumbai, India

T. Aziz, S. Dugad, G. Kole, B. Mahakud, S. Mitra, G.B. Mohanty, B. Parida, N. Sur, B. Sutar

Tata Institute of Fundamental Research-B, Mumbai, India

S. Banerjee, R.K. Dewanjee, S. Ganguly, M. Guchait, Sa. Jain, S. Kumar, M. Maity24, G. Majumder, K. Mazumdar, T. Sarkar24, N. Wickramage27

Indian Institute of Science Education and Research (IISER), Pune, India S. Chauhan, S. Dube, V. Hegde, A. Kapoor, K. Kothekar, S. Pandey, A. Rane, S. Sharma Institute for Research in Fundamental Sciences (IPM), Tehran, Iran

S. Chenarani28, E. Eskandari Tadavani, S.M. Etesami28, M. Khakzad, M. Mohammadi Najafabadi, M. Naseri, S. Paktinat Mehdiabadi29, F. Rezaei Hosseinabadi, B. Safarzadeh30, M. Zeinali

University College Dublin, Dublin, Ireland M. Felcini, M. Grunewald

INFN Sezione di Bari a, Universit`a di Bari b, Politecnico di Bari c, Bari, Italy M. Abbresciaa,b, C. Calabriaa,b, C. Caputoa,b, A. Colaleoa, D. Creanzaa,c, L. Cristellaa,b, N. De Filippisa,c, M. De Palmaa,b, L. Fiorea, G. Iasellia,c, G. Maggia,c, M. Maggia, G. Minielloa,b, S. Mya,b, S. Nuzzoa,b, A. Pompilia,b, G. Pugliesea,c, R. Radognaa,b, A. Ranieria, G. Selvaggia,b, A. Sharmaa, L. Silvestrisa,16, R. Vendittia,b, P. Verwilligena INFN Sezione di Bologna a, Universit`a di Bologna b, Bologna, Italy

G. Abbiendia, C. Battilana, D. Bonacorsia,b, S. Braibant-Giacomellia,b, L. Brigliadoria,b, R. Campaninia,b, P. Capiluppia,b, A. Castroa,b, F.R. Cavalloa, S.S. Chhibraa,b, G. Codispotia,b, M. Cuffiania,b, G.M. Dallavallea, F. Fabbria, A. Fanfania,b, D. Fasanellaa,b, P. Giacomellia, C. Grandia, L. Guiduccia,b, S. Marcellinia, G. Masettia, A. Montanaria, F.L. Navarriaa,b_{, A. Perrotta}a_{, A.M. Rossi}a,b_{, T. Rovelli}a,b_{, G.P. Siroli}a,b_{, N. Tosi}a,b,16

INFN Sezione di Catania a, Universit`a di Catania b, Catania, Italy

S. Albergoa,b, S. Costaa,b, A. Di Mattiaa, F. Giordanoa,b, R. Potenzaa,b, A. Tricomia,b, C. Tuvea,b

INFN Sezione di Firenze a, Universit`a di Firenze b, Firenze, Italy

G. Barbaglia, V. Ciullia,b, C. Civininia, R. D’Alessandroa,b, E. Focardia,b, P. Lenzia,b, M. Meschinia, S. Paolettia, L. Russoa,31, G. Sguazzonia, D. Stroma, L. Viliania,b,16 INFN Laboratori Nazionali di Frascati, Frascati, Italy

JHEP07(2017)121

INFN Sezione di Genova a, Universit`a di Genova b, Genova, Italy V. Calvellia,b, F. Ferroa, M.R. Mongea,b, E. Robuttia, S. Tosia,b

INFN Sezione di Milano-Bicocca a, Universit`a di Milano-Bicocca b, Milano, Italy

L. Brianzaa,b,16, F. Brivioa,b, V. Ciriolo, M.E. Dinardoa,b, S. Fiorendia,b,16, S. Gennaia, A. Ghezzia,b, P. Govonia,b, M. Malbertia,b, S. Malvezzia, R.A. Manzonia,b, D. Menascea, L. Moronia, M. Paganonia,b, D. Pedrinia, S. Pigazzinia,b, S. Ragazzia,b, T. Tabarelli de Fatisa,b

INFN Sezione di Napoli a, Universit`a di Napoli ’Federico II’ b, Napoli, Italy, Universit`a della Basilicata c_{, Potenza, Italy, Universit`a G. Marconi} d_{, Roma,}

Italy

S. Buontempoa, N. Cavalloa,c, G. De Nardo, S. Di Guidaa,d,16, M. Espositoa,b, F. Fabozzia,c, F. Fiengaa,b, A.O.M. Iorioa,b, G. Lanzaa, L. Listaa, S. Meolaa,d,16, P. Paoluccia,16, C. Sciaccaa,b, F. Thyssena

INFN Sezione di Padova a, Universit`a di Padovab, Padova, Italy, Universit`a di Trento c, Trento, Italy

P. Azzia,16_{, N. Bacchetta}a_{, L. Benato}a,b_{, A. Boletti}a,b_{, A. Carvalho Antunes De Oliveira}a,b_,

P. Checchiaa, M. Dall’Ossoa,b, P. De Castro Manzanoa, T. Dorigoa, U. Dossellia, S. Fantinela, F. Fanzagoa, F. Gasparinia,b, U. Gasparinia,b, A. Gozzelinoa, S. Lacapraraa, M. Margonia,b_{, A.T. Meneguzzo}a,b_{, J. Pazzini}a,b_{, N. Pozzobon}a,b_{, P. Ronchese}a,b_,

F. Simonettoa,b, E. Torassaa, S. Venturaa, M. Zanettia,b, P. Zottoa,b INFN Sezione di Pavia a, Universit`a di Pavia b, Pavia, Italy

A. Braghieria, F. Fallavollitaa,b, A. Magnania,b, P. Montagnaa,b, S.P. Rattia,b, V. Rea, C. Riccardia,b, P. Salvinia, I. Vaia,b, P. Vituloa,b

INFN Sezione di Perugia a, Universit`a di Perugia b, Perugia, Italy

L. Alunni Solestizia,b, G.M. Bileia, D. Ciangottinia,b, L. Fan`oa,b, P. Laricciaa,b, R. Leonardia,b, G. Mantovania,b, V. Mariania,b, M. Menichellia, A. Sahaa, A. Santocchiaa,b INFN Sezione di Pisa a, Universit`a di Pisa b, Scuola Normale Superiore di Pisa c, Pisa, Italy

K. Androsova,31_{, P. Azzurri}a,16_{, G. Bagliesi}a_{, J. Bernardini}a_{, T. Boccali}a_{, R. Castaldi}a_,

M.A. Cioccia,31, R. Dell’Orsoa, S. Donatoa,c, G. Fedi, A. Giassia, M.T. Grippoa,31, F. Ligabuea,c, T. Lomtadzea, L. Martinia,b, A. Messineoa,b, F. Pallaa, A. Rizzia,b, A. Savoy-Navarroa,32_{, P. Spagnolo}a_{, R. Tenchini}a_{, G. Tonelli}a,b_{, A. Venturi}a_{, P.G. Verdini}a

INFN Sezione di Roma a, Universit`a di Roma b, Roma, Italy

L. Baronea,b, F. Cavallaria, M. Cipriania,b, D. Del Rea,b,16, M. Diemoza, S. Gellia,b, E. Longoa,b, F. Margarolia,b, B. Marzocchia,b, P. Meridiania, G. Organtinia,b, R. Paramattia,b, F. Preiatoa,b, S. Rahatloua,b, C. Rovellia, F. Santanastasioa,b

JHEP07(2017)121

INFN Sezione di Torino a, Universit`a di Torino b, Torino, Italy, Universit`a del Piemonte Orientale c, Novara, Italy

N. Amapanea,b_{, R. Arcidiacono}a,c,16_{, S. Argiro}a,b_{, M. Arneodo}a,c_{, N. Bartosik}a_,

R. Bellana,b, C. Biinoa, N. Cartigliaa, F. Cennaa,b, M. Costaa,b, R. Covarellia,b, A. Deganoa,b, N. Demariaa, L. Fincoa,b, B. Kiania,b, C. Mariottia, S. Masellia, E. Migliorea,b_{, V. Monaco}a,b_{, E. Monteil}a,b_{, M. Monteno}a_{, M.M. Obertino}a,b_{, L. Pacher}a,b_,

N. Pastronea, M. Pelliccionia, G.L. Pinna Angionia,b, F. Raveraa,b, A. Romeroa,b, M. Ruspaa,c, R. Sacchia,b, K. Shchelinaa,b, V. Solaa, A. Solanoa,b, A. Staianoa, P. Traczyka,b

INFN Sezione di Trieste a, Universit`a di Trieste b, Trieste, Italy S. Belfortea, M. Casarsaa, F. Cossuttia, G. Della Riccaa,b, A. Zanettia Kyungpook National University, Daegu, Korea

D.H. Kim, G.N. Kim, M.S. Kim, S. Lee, S.W. Lee, Y.D. Oh, S. Sekmen, D.C. Son, Y.C. Yang

Chonbuk National University, Jeonju, Korea A. Lee

Chonnam National University, Institute for Universe and Elementary Particles, Kwangju, Korea

H. Kim

Hanyang University, Seoul, Korea J.A. Brochero Cifuentes, T.J. Kim Korea University, Seoul, Korea

S. Cho, S. Choi, Y. Go, D. Gyun, S. Ha, B. Hong, Y. Jo, Y. Kim, K. Lee, K.S. Lee, S. Lee, J. Lim, S.K. Park, Y. Roh

Seoul National University, Seoul, Korea

J. Almond, J. Kim, H. Lee, S.B. Oh, B.C. Radburn-Smith, S.h. Seo, U.K. Yang, H.D. Yoo, G.B. Yu

University of Seoul, Seoul, Korea

M. Choi, H. Kim, J.H. Kim, J.S.H. Lee, I.C. Park, G. Ryu, M.S. Ryu Sungkyunkwan University, Suwon, Korea

Y. Choi, J. Goh, C. Hwang, J. Lee, I. Yu Vilnius University, Vilnius, Lithuania V. Dudenas, A. Juodagalvis, J. Vaitkus

National Centre for Particle Physics, Universiti Malaya, Kuala Lumpur, Malaysia

I. Ahmed, Z.A. Ibrahim, M.A.B. Md Ali33, F. Mohamad Idris34, W.A.T. Wan Abdullah, M.N. Yusli, Z. Zolkapli

JHEP07(2017)121

Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico H. Castilla-Valdez, E. De La Cruz-Burelo, I. Heredia-De La Cruz35, A. Hernandez-Almada, R. Lopez-Fernandez, R. Maga˜na Villalba, J. Mejia Guisao, A. Sanchez-Hernandez

Universidad Iberoamericana, Mexico City, Mexico S. Carrillo Moreno, C. Oropeza Barrera, F. Vazquez Valencia

Benemerita Universidad Autonoma de Puebla, Puebla, Mexico S. Carpinteyro, I. Pedraza, H.A. Salazar Ibarguen, C. Uribe Estrada

Universidad Aut´onoma de San Luis Potos´ı, San Luis Potos´ı, Mexico A. Morelos Pineda

University of Auckland, Auckland, New Zealand D. Krofcheck

University of Canterbury, Christchurch, New Zealand P.H. Butler

National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan A. Ahmad, M. Ahmad, Q. Hassan, H.R. Hoorani, W.A. Khan, A. Saddique, M.A. Shah, M. Shoaib, M. Waqas

National Centre for Nuclear Research, Swierk, Poland

H. Bialkowska, M. Bluj, B. Boimska, T. Frueboes, M. G´orski, M. Kazana, K. Nawrocki, K. Romanowska-Rybinska, M. Szleper, P. Zalewski

Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland

K. Bunkowski, A. Byszuk36, K. Doroba, A. Kalinowski, M. Konecki, J. Krolikowski, M. Misiura, M. Olszewski, M. Walczak

Laborat´orio de Instrumenta¸c˜ao e F´ısica Experimental de Part´ıculas, Lisboa, Portugal

P. Bargassa, C. Beir˜ao Da Cruz E Silva, B. Calpas, A. Di Francesco, P. Faccioli, M. Gallinaro, J. Hollar, N. Leonardo, L. Lloret Iglesias, M.V. Nemallapudi, J. Seixas, O. Toldaiev, D. Vadruccio, J. Varela

Joint Institute for Nuclear Research, Dubna, Russia

S. Afanasiev, P. Bunin, M. Gavrilenko, I. Golutvin, I. Gorbunov, A. Kamenev, V. Karjavin, A. Lanev, A. Malakhov, V. Matveev37,38_{, V. Palichik, V. Perelygin, S. Shmatov, S. Shulha,}

N. Skatchkov, V. Smirnov, N. Voytishin, A. Zarubin

Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia L. Chtchipounov, V. Golovtsov, Y. Ivanov, V. Kim39, E. Kuznetsova40, V. Murzin, V. Oreshkin, V. Sulimov, A. Vorobyev

Institute for Nuclear Research, Moscow, Russia

Yu. Andreev, A. Dermenev, S. Gninenko, N. Golubev, A. Karneyeu, M. Kirsanov, N. Krasnikov, A. Pashenkov, D. Tlisov, A. Toropin

JHEP07(2017)121

Institute for Theoretical and Experimental Physics, Moscow, Russia

V. Epshteyn, V. Gavrilov, N. Lychkovskaya, V. Popov, I. Pozdnyakov, G. Safronov, A. Spiridonov, M. Toms, E. Vlasov, A. Zhokin

Moscow Institute of Physics and Technology, Moscow, Russia T. Aushev, A. Bylinkin38

National Research Nuclear University ’Moscow Engineering Physics Insti-tute’ (MEPhI), Moscow, Russia

M. Chadeeva41, O. Markin, V. Rusinov

P.N. Lebedev Physical Institute, Moscow, Russia

V. Andreev, M. Azarkin38, I. Dremin38, M. Kirakosyan, A. Leonidov38, A. Terkulov Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia

A. Baskakov, A. Belyaev, E. Boos, V. Bunichev, M. Dubinin42, L. Dudko, A. Er-shov, V. Klyukhin, O. Kodolova, I. Lokhtin, I. Miagkov, S. Obraztsov, M. Perfilov, S. Petrushanko, V. Savrin

Novosibirsk State University (NSU), Novosibirsk, Russia V. Blinov43, Y.Skovpen43, D. Shtol43

State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, Russia

I. Azhgirey, I. Bayshev, S. Bitioukov, D. Elumakhov, V. Kachanov, A. Kalinin, D. Kon-stantinov, V. Krychkine, V. Petrov, R. Ryutin, A. Sobol, S. Troshin, N. Tyurin, A. Uzunian, A. Volkov

University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia

P. Adzic44, P. Cirkovic, D. Devetak, M. Dordevic, J. Milosevic, V. Rekovic

Centro de Investigaciones Energ´eticas Medioambientales y Tec-nol´ogicas (CIEMAT), Madrid, Spain

J. Alcaraz Maestre, M. Barrio Luna, E. Calvo, M. Cerrada, M. Chamizo Llatas, N. Col-ino, B. De La Cruz, A. Delgado Peris, A. Escalante Del Valle, C. Fernandez Bedoya, J.P. Fern´andez Ramos, J. Flix, M.C. Fouz, P. Garcia-Abia, O. Gonzalez Lopez, S. Goy Lopez, J.M. Hernandez, M.I. Josa, E. Navarro De Martino, A. P´erez-Calero Yzquierdo, J. Puerta Pelayo, A. Quintario Olmeda, I. Redondo, L. Romero, M.S. Soares

Universidad Aut´onoma de Madrid, Madrid, Spain J.F. de Troc´oniz, M. Missiroli, D. Moran

Universidad de Oviedo, Oviedo, Spain

J. Cuevas, J. Fernandez Menendez, I. Gonzalez Caballero, J.R. Gonz´alez Fern´andez, E. Palencia Cortezon, S. Sanchez Cruz, I. Su´arez Andr´es, P. Vischia, J.M. Vizan Garcia

JHEP07(2017)121

Instituto de F´ısica de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, Spain

I.J. Cabrillo, A. Calderon, E. Curras, M. Fernandez, J. Garcia-Ferrero, G. Gomez, A. Lopez Virto, J. Marco, C. Martinez Rivero, F. Matorras, J. Piedra Gomez, T. Rodrigo, A. Ruiz-Jimeno, L. Scodellaro, N. Trevisani, I. Vila, R. Vilar Cortabitarte

CERN, European Organization for Nuclear Research, Geneva, Switzerland D. Abbaneo, E. Auffray, G. Auzinger, P. Baillon, A.H. Ball, D. Barney, P. Bloch, A. Bocci, C. Botta, T. Camporesi, R. Castello, M. Cepeda, G. Cerminara, Y. Chen, A. Cimmino, D. d’Enterria, A. Dabrowski, V. Daponte, A. David, M. De Gruttola, A. De Roeck, E. Di Marco45, M. Dobson, B. Dorney, T. du Pree, D. Duggan, M. D¨unser, N. Dupont, A. Elliott-Peisert, P. Everaerts, S. Fartoukh, G. Franzoni, J. Fulcher, W. Funk, D. Gigi, K. Gill, M. Girone, F. Glege, D. Gulhan, S. Gundacker, M. Guthoff, P. Harris, J. Hegeman, V. Innocente, P. Janot, J. Kieseler, H. Kirschenmann, V. Kn¨unz, A. Kornmayer16, M.J. Ko-rtelainen, K. Kousouris, M. Krammer1, C. Lange, P. Lecoq, C. Louren¸co, M.T. Lucchini, L. Malgeri, M. Mannelli, A. Martelli, F. Meijers, J.A. Merlin, S. Mersi, E. Meschi, P. Milenovic46, F. Moortgat, S. Morovic, M. Mulders, H. Neugebauer, S. Orfanelli, L. Orsini, L. Pape, E. Perez, M. Peruzzi, A. Petrilli, G. Petrucciani, A. Pfeiffer, M. Pierini, A. Racz, T. Reis, G. Rolandi47, M. Rovere, H. Sakulin, J.B. Sauvan, C. Sch¨afer, C. Schwick, M. Seidel, A. Sharma, P. Silva, P. Sphicas48, J. Steggemann, M. Stoye, Y. Takahashi, M. Tosi, D. Treille, A. Triossi, A. Tsirou, V. Veckalns49, G.I. Veres21, M. Verweij, N. Wardle, H.K. W¨ohri, A. Zagozdzinska36, W.D. Zeuner

Paul Scherrer Institut, Villigen, Switzerland

W. Bertl, K. Deiters, W. Erdmann, R. Horisberger, Q. Ingram, H.C. Kaestli, D. Kotlinski, U. Langenegger, T. Rohe, S.A. Wiederkehr

Institute for Particle Physics, ETH Zurich, Zurich, Switzerland

F. Bachmair, L. B¨ani, L. Bianchini, B. Casal, G. Dissertori, M. Dittmar, M. Doneg`a, C. Grab, C. Heidegger, D. Hits, J. Hoss, G. Kasieczka, W. Lustermann, B. Mangano, M. Marionneau, P. Martinez Ruiz del Arbol, M. Masciovecchio, M.T. Meinhard, D. Meister, F. Micheli, P. Musella, F. Nessi-Tedaldi, F. Pandolfi, J. Pata, F. Pauss, G. Perrin, L. Perrozzi, M. Quittnat, M. Rossini, M. Sch¨onenberger, A. Starodumov50, V.R. Tavolaro, K. Theofilatos, R. Wallny

Universit¨at Z¨urich, Zurich, Switzerland

T.K. Aarrestad, C. Amsler51_{, L. Caminada, M.F. Canelli, A. De Cosa, C. Galloni,}

A. Hinzmann, T. Hreus, B. Kilminster, J. Ngadiuba, D. Pinna, G. Rauco, P. Robmann, D. Salerno, C. Seitz, Y. Yang, A. Zucchetta

National Central University, Chung-Li, Taiwan

V. Candelise, T.H. Doan, Sh. Jain, R. Khurana, M. Konyushikhin, C.M. Kuo, W. Lin, A. Pozdnyakov, S.S. Yu

JHEP07(2017)121

National Taiwan University (NTU), Taipei, Taiwan

Arun Kumar, P. Chang, Y.H. Chang, Y. Chao, K.F. Chen, P.H. Chen, F. Fiori, W.-S. Hou, Y. Hsiung, Y.F. Liu, R.-S. Lu, M. Mi˜nano Moya, E. Paganis, A. Psallidas, J.f. Tsai Chulalongkorn University, Faculty of Science, Department of Physics, Bangkok, Thailand

B. Asavapibhop, G. Singh, N. Srimanobhas, N. Suwonjandee

Cukurova University - Physics Department, Science and Art Faculty

A. Adiguzel, M.N. Bakirci52, S. Damarseckin, Z.S. Demiroglu, C. Dozen, E. Eskut, S. Girgis, G. Gokbulut, Y. Guler, I. Hos53, E.E. Kangal54, O. Kara, U. Kiminsu, M. Oglakci, G. Onengut55, K. Ozdemir56, S. Ozturk52, A. Polatoz, D. Sunar Cerci57, S. Turkcapar, I.S. Zorbakir, C. Zorbilmez

Middle East Technical University, Physics Department, Ankara, Turkey B. Bilin, S. Bilmis, B. Isildak58, G. Karapinar59, M. Yalvac, M. Zeyrek

Bogazici University, Istanbul, Turkey

E. G¨ulmez, M. Kaya60, O. Kaya61, E.A. Yetkin62, T. Yetkin63 Istanbul Technical University, Istanbul, Turkey

A. Cakir, K. Cankocak, S. Sen64

Institute for Scintillation Materials of National Academy of Science of Ukraine, Kharkov, Ukraine

B. Grynyov

National Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, Ukraine

L. Levchuk, P. Sorokin

University of Bristol, Bristol, United Kingdom

R. Aggleton, F. Ball, L. Beck, J.J. Brooke, D. Burns, E. Clement, D. Cussans, H. Flacher, J. Goldstein, M. Grimes, G.P. Heath, H.F. Heath, J. Jacob, L. Kreczko, C. Lucas, D.M. Newbold65_{, S. Paramesvaran, A. Poll, T. Sakuma, S. Seif El Nasr-storey, D. Smith,}

V.J. Smith

Rutherford Appleton Laboratory, Didcot, United Kingdom

K.W. Bell, A. Belyaev66, C. Brew, R.M. Brown, L. Calligaris, D. Cieri, D.J.A. Cockerill, J.A. Coughlan, K. Harder, S. Harper, E. Olaiya, D. Petyt, C.H. Shepherd-Themistocleous, A. Thea, I.R. Tomalin, T. Williams

Imperial College, London, United Kingdom

M. Baber, R. Bainbridge, O. Buchmuller, A. Bundock, D. Burton, S. Casasso, M. Citron, D. Colling, L. Corpe, P. Dauncey, G. Davies, A. De Wit, M. Della Negra, R. Di Maria, P. Dunne, A. Elwood, D. Futyan, Y. Haddad, G. Hall, G. Iles, T. James, R. Lane, C. Laner, R. Lucas65, L. Lyons, A.-M. Magnan, S. Malik, L. Mastrolorenzo, J. Nash, A. Nikitenko50, J. Pela, B. Penning, M. Pesaresi, D.M. Raymond, A. Richards, A. Rose, E. Scott, C. Seez, S. Summers, A. Tapper, K. Uchida, M. Vazquez Acosta67, T. Virdee16, J. Wright, S.C. Zenz